阅读说明：本技术 使用压缩机再循环阀和涡轮增压器废气门改善发动机转速稳定性和性能的压缩机出口压力控制 (Compressor outlet pressure control using compressor recirculation valve and turbocharger wastegate to improve engine speed stability and performance ) 是由 M·H·哈尔贝 R·J·托马斯 谢明峰 于 2018-11-06 设计创作，主要内容包括：公开了用于通过基于目标压缩机出口压力将压缩机再循环阀和涡轮增压器废气门打开或关闭到命令位置来产生所述目标压缩机出口压力的系统、方法和设备,所述目标压缩机出口压力是基于内燃发动机的进气节气门两端的期望压力差和进气歧管压力。(Systems, methods, and apparatus are disclosed for generating a target compressor outlet pressure by opening or closing a compressor recirculation valve and a turbocharger wastegate to a commanded position based on the target compressor outlet pressure, which is based on a desired pressure differential across an intake throttle and an intake manifold pressure of an internal combustion engine.)

1. A method, comprising:

determining a target pressure difference across an intake throttle of an internal combustion engine, the internal combustion engine comprising a turbocharger having a compressor and a compressor recirculation valve, the compressor recirculation valve comprising a first controllable actuator for controlling a position of the compressor recirculation valve, the turbocharger further comprising a turbine having a turbine bypass and a wastegate, the wastegate comprising a second controllable actuator for controlling a position of the wastegate in the turbine bypass;

determining a target compressor outlet pressure in response to an intake manifold pressure of the internal combustion engine and a target pressure differential across the intake throttle;

determining a compressor outlet pressure correction using a feedback control output in response to the target compressor outlet pressure and an actual compressor outlet pressure;

determining a compressor recirculation valve position command for the first controllable actuator based on the feedback control output to provide a first portion of the compressor outlet pressure correction;

determining a wastegate position command for the second controllable actuator based on the feedback control output to provide a second portion of the compressor outlet pressure correction; and

positioning the compressor recirculation valve with the first controllable actuator in response to the compressor recirculation valve position command and positioning the wastegate with the second controllable actuator in response to the wastegate actuator position command.

2. The method of claim 1, wherein the internal combustion engine includes a charge cooler upstream of the intake throttle and downstream of the compressor of the turbocharger.

3. The method of claim 1, wherein the first portion of the compressor outlet pressure correction comprises proportional, derivative, and integral feedback control responses.

4. The method of claim 3, wherein the second portion of the compressor outlet pressure correction comprises proportional, derivative, and integral feedback control responses.

5. The method of claim 1, wherein the target compressor outlet pressure is constant during steady state engine operating conditions.

6. The method of claim 1, wherein the target compressor outlet pressure varies in response to a threshold variation in the intake manifold pressure.

7. An apparatus, comprising:

an electronic controller configured to determine a compressor recirculation valve command in response to a feedback control output, the compressor recirculation valve command controlling a compressor recirculation valve actuator to position a compressor recirculation valve in a compressor recirculation flow path of an internal combustion engine, the electronic controller further configured to determine a wastegate actuator position command in response to the feedback control output, the wastegate actuator position command controlling a wastegate actuator to position a wastegate in a turbine bypass of the internal combustion engine, wherein the feedback control output provides a target compressor outlet pressure upstream of the internal combustion engine; and is

Wherein to provide the target compressor outlet pressure, the compressor recirculation valve actuator is operable to position the compressor recirculation valve in response to the compressor recirculation valve command, and the wastegate actuator is operable to position the wastegate in response to the wastegate actuator position command.

8. The apparatus of claim 7, wherein the controller determines the target compressor outlet pressure in response to an intake manifold pressure of an intake manifold of the internal combustion engine and a target intake throttle pressure difference of an intake throttle upstream of the intake manifold.

9. The apparatus of claim 8, wherein the target compressor outlet pressure varies in response to a threshold variation in the intake manifold pressure.

10. The plant of claim 7 wherein the feedback control output comprises a target compressor outlet pressure correction and the electronic controller is configured to determine the compressor recirculation valve position command for a first portion of the compressor outlet pressure correction and the electronic controller is configured to determine the wastegate position command for a second portion of the compressor outlet pressure correction.

11. The apparatus of claim 10, wherein the first portion of the compressor outlet pressure correction is based on a proportional, integral, and derivative feedback control response.

12. The apparatus of claim 11, wherein the second portion of the compressor outlet pressure correction is based on a proportional, integral, and derivative feedback control response.

13. The apparatus of claim 7, wherein the target compressor outlet pressure is constant during steady state engine operating conditions.

14. A system, comprising:

an internal combustion engine pneumatically coupled to a compressor of a turbocharger on an inlet side of the engine and pneumatically coupled to a turbine of the turbocharger on an outlet side of the engine, the inlet side of the internal combustion engine further including an intake throttle, the compressor including a compressor recirculation flow path and a compressor recirculation valve in the compressor recirculation flow path, the compressor recirculation valve connected to a compressor recirculation valve actuator in response to a compressor recirculation valve actuator command, the turbine including a wastegate connected to a wastegate actuator in response to a wastegate actuator position command; and

a controller configured to determine a compressor outlet pressure correction in response to a target compressor outlet pressure and an actual compressor outlet pressure, the compressor recirculation valve command is based on a first portion of the compressor outlet pressure correction to adjust a position of the compressor recirculation valve with the compressor recirculation valve actuator, and the wastegate actuator position command is based on a second portion of the compressor outlet pressure correction to adjust a position of the wastegate with the wastegate actuator.

15. The system of claim 14, wherein the controller is configured to determine the target compressor outlet pressure in response to an intake manifold pressure of an intake manifold of the internal combustion engine and a target intake throttle pressure difference across the intake throttle.

16. The system of claim 14, wherein the controller is configured to determine the compressor outlet pressure correction via a feedback control output.

17. The system of claim 16, wherein the target compressor outlet pressure varies in response to a threshold variation in the intake manifold pressure.

18. The system of claim 17, wherein the controller is a proportional, derivative, and integral controller configured to determine the first portion of the target compressor outlet pressure correction as a proportional, integral, and derivative feedback control response.

19. The system of claim 17, wherein the controller is a proportional-integral-derivative controller configured to determine the first portion of the target compressor outlet pressure correction as a proportional, derivative, and integral feedback control response and the second portion of the compressor outlet pressure correction as a proportional, derivative, and integral feedback control response.

20. The system of claim 14, further comprising:

a charge cooler between the intake throttle and the compressor of the turbocharger; and

an exhaust gas recirculation system connecting the inlet side and the outlet side of the engine.

Background

Certain types of engines have uncertainty in combustion due to various noise factors, such as fuel quality and environmental conditions. For example, for lean-burn natural gas engines, variations in fuel quality and environmental conditions can be particularly problematic. The steady-state brake thermal efficiency can be improved by minimizing the pressure loss across the intake throttle. However, as the intake throttle approaches the wide-open position, the valve dynamics dictate that the flow changes across the valve are small, which limits the ability to control engine speed using the intake throttle. Therefore, further technical developments are needed in this field.

Disclosure of Invention

Unique systems, methods, and apparatus are disclosed for providing a target pressure differential across an intake throttle of an internal combustion engine (i.e., engine boost or torque reserve) by controlling a compressor recirculation valve position and a turbocharger waste gate position to commanded positions.

This summary is provided to introduce a selection of concepts that are further described below in the illustrative embodiments. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter. Other embodiments, forms, objects, features, advantages, aspects, and benefits shall become apparent from the following description and drawings.

Drawings

FIG. 1 is a schematic diagram of a system including an intake throttle, a compressor recirculation valve, and a turbocharger having a wastegate.

FIG. 2 is a flow chart of a process for controlling the position of a compressor recirculation valve and a wastegate of a turbocharger.

FIG. 3 is an exemplary graph illustrating target compressor outlet pressure over time based on intake manifold absolute pressure and desired intake throttle pressure difference.

Fig. 4A and 4B are exemplary graphs illustrating feedback control of compressor recirculation valve and wastegate positioning to achieve a target compressor outlet pressure.

FIG. 5 is a schematic diagram of a processing subsystem for controlling compressor outlet pressure by adjusting the position of a compressor recirculation valve and a wastegate of a turbocharger.

Detailed Description

For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated embodiments, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.

Referring to FIG. 1, a system 100 for controlling a turbocharger 102 is schematically illustrated. The system 100 includes an internal combustion engine 114, which may be any type of engine including at least compression ignition engines, spark ignition engines, diesel engines, gasoline engines, natural gas engines, and combinations thereof. The engine 114 exhausts the exhaust gas 112 through an exhaust manifold 142, and the exhaust gas 112 flows in an exhaust conduit 113 to the turbocharger 102 and transfers a portion of the kinetic and/or thermodynamic energy of the exhaust gas to the turbine 108 of the turbocharger 102. The transferred energy passes through the shaft 106 of the turbocharger 102 to the compressor 104 of the turbocharger 102. Compressor 104 provides compressed intake air 110 to engine 114 using intake air conduit 111.

The compressed intake flow 110 is sometimes referred to as charge air, charge gas, charge flow, intake or other terms, none of which are limiting. The compressed intake air flow 110 may pass through a charge cooler 115 before being received by the engine 114. Although the charge cooler 115 helps to provide increased air density to the intake air flow 110 in the engine 114, the cooling reduces the pressure of the compressed intake air flow 110. The charge cooler may be provided as shown or arranged to provide after cooling, two-stage after cooling or any other charge cooler arrangement. The presence and operation of a charge cooler, if present, is well known and not critical to the operation of the turbocharger 102.

Intake conduit 111 also includes an intake throttle 126 that controls charge flow to an intake manifold 140 of engine 114. The intake throttle valve 126 may include a throttle actuator 128 connected to the controller 116 that controls the opening and closing of the intake throttle valve 126 to provide a desired intake air flow to the air intake of the engine 114.

Certain features, such as an exhaust throttle, an air cleaner, an intake air heater, and/or an exhaust gas recirculation cooler, may or may not be present in the system 100. The presence and operation of such features have not been depicted in order to enhance clarity of description.

The turbocharger 102 includes a wastegate 120 that allows the exhaust gas 112 to bypass the turbine 106. The wastegate 120 includes a WG valve 122 operably connected to a controllable WG actuator 124 operable to open and close the WG valve 122 to control the opening size of the wastegate 120 in response to one or more wastegate actuator position commands from the controller 116.

The turbocharger 102 also includes a compressor recirculation flow path 134 that allows the intake air flow to bypass or recirculate around the compressor 104. In the illustrated embodiment, the compressor recirculation flow path 134 is connected upstream of the charge cooler 115. In another embodiment, the compressor recirculation flow path 134 is connected downstream of the charge cooler 115. Other connection arrangements of the compressor recirculation flow path inlets and outlets are also contemplated. The compressor recirculation flow path 134 includes a Compressor Recirculation Valve (CRV)136 operatively connected to a controllable CRV actuator 138 operable to open and close the CRV136 to control the open size of the compressor recirculation flow path 134 in response to one or more compressor recirculation valve actuator position commands from the controller 116.

In one embodiment, the system 100 includes an Exhaust Gas Recirculation (EGR) flow path 130 that fluidly couples the engine exhaust side to the engine intake side. The EGR flow path 130 may fluidly couple the exhaust manifold to the intake manifold, or any other portion of the exhaust system to any other portion of the intake system. In the depicted example, although the EGR flow path 130 may include the EGR valve 132, the EGR flow path 130 may additionally or alternatively include an EGR cooler (not shown), and may also include an EGR cooler bypass (not shown). EGR flow path 130 may be coupled to the intake system at a location upstream or downstream of charge cooler 115 and upstream or downstream of intake throttle 126. The depicted EGR flow path 130 in the system 100 is a "high pressure" EGR system that couples the exhaust system upstream of the turbine 106 to the intake system downstream of the compressor 104. However, the EGR flow path 130 (if present) may additionally or alternatively be a low pressure EGR system that couples the exhaust system downstream of the turbine 108 to the intake system upstream of the compressor 104. The presence and type of EGR systems and EGR components present are entirely optional and are not limiting to the present disclosure.

System 100 includes a controller 116 structured to perform certain operations to control wastegate valve 122 and compressor recirculation valve 136. In certain embodiments, the controller 116 forms part of a processing subsystem that includes one or more computing devices having memory, processing, and communication hardware. The controller can be a single device or a distributed device, and the functions of the controller can be performed by hardware and/or by a computer executing instructions stored in a non-transitory memory on one or more computer readable media.

In certain embodiments, the controller includes one or more modules structured to functionally execute the operations of the controller. The description herein including modules emphasizes the structural independence of the aspects of the controller and illustrates the operation and responsibility groupings of the controller. Other groupings that perform similar overall operations are understood to be within the scope of this application. Modules may be implemented in hardware and/or by a computer executing instructions stored in a non-transitory memory on one or more computer-readable media, and may be distributed across various hardware or computer-based components.

Exemplary and non-limiting module implementation elements include sensors that provide any value determined herein, sensors that provide any value that is a precursor to a value determined herein, data link and/or networking hardware including communication chips, oscillating crystals, communication links, cables, twisted pair wires, coaxial wires, shielded wires, transmitters, receivers and/or transceivers, logic circuits, hardwired logic circuits, reconfigurable logic circuits in a particular non-transient state configured according to a module specification, any actuator including at least one electrical, hydraulic or pneumatic actuator, solenoids, operational amplifiers, analog control elements (springs, filters, integrators, adders, dividers, gain elements), and/or digital control elements.

The list of specific implementation elements herein is not limiting, and any implementation elements for any module or controller described herein that would be understood by one of ordinary skill in the art are contemplated herein. Once the operations are described, the modules and controllers herein can have a variety of hardware and/or computer-based embodiments, many of which relate to mechanical steps that would be useful to one of ordinary skill in the art having the benefit of this disclosure and understanding the operations of the modules and controllers provided by this disclosure. A more detailed description of certain embodiments of the controller operation is included in the section referencing fig. 5.

Certain operations described herein include operations for interpreting or determining one or more parameters. As utilized herein, interpreting or determining includes making the value available to any method known in the art, including at least receiving the value from a data link or network communication, receiving an electronic signal (e.g., a voltage, frequency, current, or PWM signal) indicative of the value, receiving a computer-generated parameter indicative of the value, reading the value from a memory location on a non-transitory computer-readable storage medium, receiving the value as a runtime parameter by any method known in the art (e.g., from an operator input), receiving a value by which the interpreted or determined parameter can be calculated, and/or interpreted or determined by reference as a default value for the parameter value.

The following schematic flow chart and associated description provide exemplary embodiments of processes for controlling wastegate and compressor recirculation valve positions in response to a pressure differential across an intake throttle to provide a desired or requested engine boost or torque reserve. The operations shown are to be understood as exemplary only, and operations may be combined or divided and added or deleted and reordered in whole or in part unless stated to the contrary herein. Certain operations illustrated may be implemented by a computer executing a computer program product on a non-transitory computer readable storage medium, where the computer program product includes instructions to cause the computer to perform one or more operations or issue commands to other devices to perform one or more operations.

FIG. 2 is a flow diagram of one embodiment of a process 200 for controlling compressor exit pressure (COP) using compressor recirculation valve 136 and wastegate valve 122 to improve rotational speed stability and performance of engine 114. The control systems, processes, and devices disclosed herein improve system robustness due to uncertainties in the combustion process caused by, for example, environmental conditions and fuel quality. COP is considered to reasonably represent combustion uncertainty, so controlling COP to a desired target may improve engine robustness and performance.

IT is desirable to minimize pressure loss across the Intake Throttle (IT)126 in order to improve steady state brake thermal efficiency. However, when IT126 is at or near full opening, the valve dynamics indicate that the flow changes across IT126 are small and this limits the controllability of the engine speed. In this case, if the COP is controlled, the input of the engine system is stable, and contributes to stabilization and improvement of the engine performance.

The pressure loss across IT126 is essentially the difference between the COP and the intake Manifold Absolute Pressure (MAP). A Throttle Pressure Loss (TPL) target is used to generate a compressor outlet pressure target. Process 200 includes an operation 202 to measure an intake Manifold Absolute Pressure (MAP). The process 200 continues at operation 204 to determine a target IT pressure differential. The process 200 also includes an operation 206 to determine a target COP. The target COP is determined as the sum of the MAP and TPL targets. When IT126 has a limit to controllability of the engine speed due to a low TPL, COP inputted into the system is kept constant to improve speed stability. The target COP may gradually increase or decrease when the MAP changes by more than a threshold amount due to environmental conditions or combustion recipes. This strategy of gradually changing and maintaining the target COP effectively decouples combustion instability from boost control.

The process 200 continues at operation 208 to determine a COP correction in response to the target COP and the actual or measured COP. In one embodiment, the COP correction is determined using feedback control, such as a proportional-integral-derivative (PID) controller. Process 200 continues at operation 210 to position CRV136 based on a first portion of the COP correction and at operation 212 to position wastegate valve 122 based on a second portion of the COP correction. In response to the COP error, the controller 116 assumes a PID corrective action to position the CRV actuator 138 and a PID corrective action to position the wastegate valve 122.

In one embodiment, the first part of the COP correction is a PID correction amount where the CRV actuator 138 positions the CRV in response to a CRV actuator position command from the controller 116. The second part of the COP correction is the PID correction amount in which the WG actuator 124 positions the wastegate valve 122 in response to the WG actuator position command from the controller 116. FIG. 3 shows a graph of pressure on the y-axis and time on the x-axis for the relationship between MAP, IT126 pressure differential and MAP and COP targets. The target COP is the sum of the MAP and IT pressure differential targets. Due to combustion and ambient conditions, MAP has less uncertainty even under steady state conditions. Therefore, the sum of the MAP and IT pressure differential target also includes uncertainty, but the target COP remains constant within the hysteresis band, regardless of minor variations in the MAP. The target COP only changes in response to a threshold increase or decrease in MAP, such as in response to a load transient, as depicted by the larger step change in MAP in fig. 3.

Fig. 4A shows the target COP and COP feedback over time. In steady state, the target COP remains constant regardless of the noise affecting MAP. When a load step change that causes a MAP change occurs as depicted in fig. 4A, the target COP may change, and in response, the feedback control of the COP may change the actual COP. FIG. 4B depicts a fast actuation of the CRV136 by using PID action control and a slow actuation of the WG valve 12 by using PID action control.

The positioning of the WG valve 122 affects turbine speed, while the position of the CRV136 redirects a certain amount of boost flow through the compressor 104. The sensitivity of the COP differs for the two actuators. While control of the WG valve 122 is an important means of controlling COP, engine speed stability is also improved when the CRV136 is actuated fast enough to eliminate combustion uncertainty. Thus, feedback control of the COP is provided with a PID type controller 116, wherein PID action control of the CRV136 is employed in conjunction with the PID action of the WG valve 122.

One embodiment process includes operations for determining a CRV actuator position command by selecting a CRV actuator position command from a plurality of CRV actuator position command solution values. Exemplary operations for selecting a CRV actuator position command from a plurality of CRV actuator position command solution values include selecting a CRV actuator position command that provides a target exhaust flow through the compressor recirculation flow path 134 and/or through the compressor 104, and selecting the CRV actuator position command that is closest to the target exhaust flow through the compressor recirculation flow path 134 and/or the compressor 104.

Another example process includes an operation for determining a wastegate actuator position command by selecting a wastegate actuator position command from a plurality of wastegate actuator position command solution values. Exemplary operations for selecting a wastegate actuator position command from a plurality of wastegate actuator position command solution values include selecting a wastegate actuator position command that provides a target exhaust flow through wastegate 120 and/or turbine 108 and selecting a wastegate actuator position command that is closest to the target exhaust flow through wastegate 120 and/or turbine 108.

The target IT126 pressure differential may be determined according to any operation known in the art having the benefit of the present disclosure. Exemplary and non-limiting operations for determining a target IT126 pressure differential include at least determining: a pressure differential corresponding to a load threshold (e.g., 10%, 25%, etc.), which may be a maximum load, a load at a current engine speed, or other load value; specific pressure differences in absolute terms (e.g., 20psia, 25psia, 30psia, etc.); and/or pressure differential values at which empirical testing indicates that the CRV136 and wastegate valve 122 have sufficient responsiveness under normal actuator position control schemes. The value of "sufficient responsiveness" may be defined by meeting transient requirements, by meeting engine speed or air flow rise time requirements, by meeting operability specifications, and/or by meeting transient requirements to meet operability, emissions, transient, or other system delivery requirements.

Fig. 5 is a schematic diagram of a processing subsystem 300 that includes the controller 116. The exemplary processing subsystem 300 for the controller 116 includes a reference generation module 302, a feedback control module 304, and an actuator positioning module 306. Other modules may also be present, and the described modules may be combined or further separated into additional modules, and are not limited to the described modules.

The reference generation module 302 includes a target COP calculation 310 and an actual COP measurement 312 associated with the system 100. As discussed above, the target COP calculation 310 may be performed or based on MAP and the desired pressure differential across IT 126. The actual COP may come from a measurement of the pressure at the compressor outlet or other suitable indicator or proxy for COP.

The feedback module 304 receives the target COP and the measured or actual COP and provides these values as inputs to the feedback control processor 314. The COP controller 316 may then receive an output from the feedback control processor 314 based on the target COP and the actual COP. The COP controller 316 evaluates the feedback controller output to provide PID compensation for the CRV position command 318 to the CRV actuator 138 to position the CRV136 and PID compensation for the WG position command 320 to the WG actuator 124 to position the WG valve 122. The positions of the CRV136 and WG valve 122 are selected to provide a target COP.

Control of the engine 114 is typically operated in accordance with previously known charge flow or intake air flow target values (e.g., mass flow of air or combined air and EGR flow at the engine inlet) that may be provided by an engine controller (not shown). The engine controller may operate on the same device as controller 116 or be a separate device from the controller. The target COP may be calculated based on the intake manifold pressure (or other target intake pressure downstream of intake throttle 126 and upstream of the cylinders of engine 114) and the target intake throttle pressure difference. Additionally or alternatively, the target intake throttle pressure difference may be a direct input to the controller 116, such as provided by an engine controller.

As is apparent from the figures and text presented above, various embodiments in accordance with the present disclosure are contemplated.

According to one aspect, a method includes determining a target pressure differential across an intake throttle of an internal combustion engine. The internal combustion engine includes a turbocharger having a compressor and a compressor recirculation valve including a first controllable actuator for controlling a position of the compressor recirculation valve. The turbocharger further comprises a turbine having a turbine bypass and a wastegate, the wastegate comprising a second controllable actuator for controlling the position of the wastegate in the turbine bypass. The method further includes determining a target compressor outlet pressure in response to an intake manifold pressure of the internal combustion engine and a target pressure differential across the intake throttle; determining a compressor outlet pressure correction using a feedback control output in response to the target compressor outlet pressure and an actual compressor outlet pressure; determining a compressor recirculation valve position command for the first controllable actuator based on the feedback control output to provide a first portion of the compressor outlet pressure correction; determining a wastegate position command for the second controllable actuator based on the feedback control output to provide a second portion of the compressor outlet pressure correction; and positioning the compressor recirculation valve with the first controllable actuator in response to the compressor recirculation valve position command and positioning the wastegate with the second controllable actuator in response to the wastegate actuator position command.

In one embodiment, the internal combustion engine includes a charge cooler upstream of the intake throttle and downstream of the compressor of the turbocharger. In another embodiment, the first portion of the compressor outlet pressure correction includes proportional, derivative, and integral feedback control responses. In a refinement of this embodiment, the second portion of the compressor outlet pressure correction comprises a proportional, derivative and integral feedback control response.

In another embodiment, the target compressor outlet pressure is constant during steady state engine operating conditions. In yet another embodiment, the target compressor outlet pressure varies in response to a threshold variation in the intake manifold pressure.

In another aspect, an apparatus includes an electronic controller configured to determine a compressor recirculation valve command in response to a feedback control output, the compressor recirculation valve command controlling a compressor recirculation valve actuator to position a compressor recirculation valve in a compressor recirculation flow path of an internal combustion engine. The electronic controller is further configured to determine a wastegate actuator position command in response to the feedback control output, the wastegate actuator position command controlling a wastegate actuator to position a wastegate in a turbine bypass of the internal combustion engine. The feedback control output provides a target compressor outlet pressure upstream of the internal combustion engine. To provide the target compressor outlet pressure, the compressor recirculation valve actuator is operable to position the compressor recirculation valve in response to the compressor recirculation valve command, and the wastegate actuator is operable to position the wastegate in response to the wastegate actuator position command.

In one embodiment, the target compressor outlet pressure is constant during steady state engine operating conditions. In another embodiment, the controller determines the target compressor outlet pressure in response to an intake manifold pressure of an intake manifold of the internal combustion engine and a target intake throttle pressure differential of an intake throttle upstream of the intake manifold. In a refinement of this embodiment, the target compressor outlet pressure varies in response to a threshold variation in the intake manifold pressure.

In another embodiment, the feedback control output includes a target compressor outlet pressure correction, and the electronic controller is configured to determine the compressor recirculation valve position command for a first portion of the compressor outlet pressure correction, and the electronic controller is configured to determine the wastegate position command for a second portion of the compressor outlet pressure correction. In a refinement of this embodiment, the first portion of the compressor outlet pressure correction is based on a proportional, integral, and derivative feedback control response. In another embodiment, the second portion of the compressor outlet pressure correction is based on proportional, integral, and derivative feedback control responses.

According to yet another aspect, a system includes an internal combustion engine pneumatically coupled to a compressor of a turbocharger on an inlet side of the engine and pneumatically coupled to a turbine of the turbocharger on an outlet side of the engine. The inlet side of the internal combustion engine further includes an intake throttle, and the compressor includes a compressor recirculation flowpath and a compressor recirculation valve in the compressor recirculation flowpath, the compressor recirculation valve connected to a compressor recirculation valve actuator in response to a compressor recirculation valve actuator command. The turbine includes a wastegate, which is coupled to a wastegate actuator in response to a wastegate actuator position command. The system also includes a controller configured to determine a compressor outlet pressure correction in response to the target compressor outlet pressure and the actual compressor outlet pressure. The compressor recirculation valve command is based on a first portion of the compressor outlet pressure correction to adjust the position of the compressor recirculation valve with the compressor recirculation valve actuator, and the wastegate actuator position command is based on a second portion of the compressor outlet pressure correction to adjust the position of the wastegate with the wastegate actuator.

In one embodiment, the controller is configured to determine the target compressor outlet pressure in response to an intake manifold pressure of an intake manifold of the internal combustion engine and a target intake throttle pressure difference across the intake throttle. In another embodiment, the system includes a charge cooler between the intake throttle and the compressor of the turbocharger; and an exhaust gas recirculation system connecting the inlet side and the outlet side of the engine.

In yet another embodiment, the controller is configured to determine the compressor outlet pressure correction via a feedback control output. In a refinement of this embodiment, the target compressor outlet pressure varies in response to a threshold variation in the intake manifold pressure. In another refinement, the controller is a proportional, derivative, and integral controller configured to determine the first portion of the target compressor outlet pressure correction as a proportional, integral, and derivative feedback control response. In another refinement, the controller is a proportional-integral-derivative controller configured to determine the first portion of the target compressor outlet pressure correction as a proportional, derivative, and integral feedback control response and the second portion of the compressor outlet pressure correction as a proportional, derivative, and integral feedback control response.

While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only certain exemplary embodiments have been shown and described. It will be apparent to those skilled in the art that many modifications are possible in the exemplary embodiments without materially departing from this invention. Accordingly, all such modifications are intended to be included within the scope of this disclosure as defined in the following claims.

In reading the claims, it is intended that when words such as "a," "an," "at least one," or "at least a portion" are used, there is no intention to limit the claims to only one item unless specifically stated to the contrary in the claims. When the language "at least a portion" and/or "a portion" is used, the item can include a portion and/or the entire item unless specifically stated to the contrary.